1. Technical Field
The present invention relates generally to technology for measuring the position of a stereo camera composed of two cameras in real time using feature points installed on an object.
2. Description of the Related Art
Technologies for calculating in real time the position of a stereo camera by observing feature points present in space using the stereo camera have been widely used in the academic world and the industrial world, including a three-dimensional (3D) scanner, a mobile robot, and a human-computer interface. Among these technologies, technology for calculating the position of a camera using randomly arranged feature points without previously knowing the positions of the feature points may be regarded as being highly useful due to the convenience of construction. Among these technologies, technology that requires a texture around feature points, which enables the feature points in sequentially input images to be distinguished from each other, may be utilized when feature points that are present in the texture of the original background are used without requiring feature points to be intentionally arranged. However, when there is an insufficient texture and feature points arranged by a user are used, there is inconvenience in which an identifiable texture or individual identification markers must be additionally arranged around the feature points. In conventional technology, there is a method for detecting, as the characteristics of only respective feature points, distances to neighboring feature points based on the 3D positions of the feature points, which are reconstructed via triangulation using stereo images, thus distinguishing the feature points. However, there may occur the case where it is ambiguous to distinguish such feature points using only this method.
U.S. Pat. No. 7,925,049 discloses technology for receiving images of a stereo camera, distinguishing feature points from each other using the background texture of the images, and tracking the images.
However, the technology of U.S. Pat. No. 7,925,049 is fatally disadvantageous in that it is impossible to precisely distinguish feature points unless a background texture is present.
Therefore, there is a need for technology that precisely distinguishes feature points from each other without using a texture or the like, present in a background, and measures the position of the camera based on the feature points.